294 THE AMERICAN MONTHLY [Oct., 



quantity of material from one of these pseudotubercles 

 introduced into the body of a susceptible animal will not 

 give rise to tuberculosis ; while if an- equal amount of 

 material from a true tubercular nodule be introduced, the 

 result will be tuberculosis in the inoculated animal. 



In addition to this experimental data, clinical evidence 

 has been accumulated which is deemed sufficient to estab- 

 lish the communicability of tuberculosis. And, if com- 

 municable, how shall we explain the power of tuberculo- 

 sis to propagate itself, in the light of our present know- 

 ledge, except upon the theory that the disease is due to a 

 contagium vivuni. 



In response to a question as to contagion, asked by a 

 committee of the British Medical Association, 261 replies 

 in the affirmative were received, among which were 158 

 cases of supposed contagion through marriage. Of these, 

 Weber's cases are of special interest. One of his patients 

 lost four wives in succession ; one three ; and four, two 

 each. 



PROOF OF ITS COMMUNICABILITY. 



Another clinical observation of interest is the fact that 

 patients received in the wards of general hospitals with 

 tubercular patients sometimes contract tuberculosis dur- 

 ing their stay and are discharged cured of the original 

 malady only to find themselves victims of tuberculosis ; 

 or, if their stay has been more protracted, remain only to 

 succumb to the latter disease. Biggs calls the attention 

 to the frequent occurrence of such cases in the hospitals 

 of New York, and the writer has observed a few similar 

 instances in the hospitals of Washington. 



Mortality statistics show the influence exerted by oc- 

 cupations requiring confinement in dust laden and crowded 

 workshops. In every thousand deaths from all causes in 

 farmers only 103 are due to pulmonary tuberculosis ; in 

 fishermen, 108 ; in gardeners, 121 ; in agricultural labor- 



